To determine which gas is most likely to depart from ideal gas behavior and which gas behaves closest to an ideal gas, we need to consider certain factors. The ideal gas law equation is PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.
1. The gas most likely to depart from ideal gas behavior:
To determine this, we need to consider the conditions under which a gas deviates from ideal behavior. Typically, gases tend to deviate from ideal behavior at high pressures and low temperatures. Additionally, if the gas molecules have strong intermolecular forces or significant molecular size, they are more likely to deviate from ideality.
From the given list of gases, the gas that is most likely to depart from ideal gas behavior is Carbon Dioxide (CO2). Carbon Dioxide molecules have a larger size compared to the other gases in the list, and they have relatively stronger intermolecular forces (due to their polarity). These factors contribute to deviations from ideal gas behavior at certain conditions.
2. The gas most likely to behave closest to an ideal gas:
To determine this, we need to consider gases that exhibit properties similar to those of an ideal gas. An ideal gas behaves in a way that the gas particles occupy negligible volume, there are no intermolecular forces between them, and collisions are completely elastic.
From the given list of gases, the gas that exhibits properties closest to an ideal gas is Helium (He). Helium is an inert gas with low molecular weight and relatively weak intermolecular forces. Its small size and low interaction potential make it behave closer to the ideal gas behavior under typical conditions.
It's important to note that while Helium behaves closest to an ideal gas, no real gas perfectly follows the ideal gas behavior. All gases, to some extent, deviate from ideality under certain conditions due to various factors like molecular interactions and volume.